Wanxiang Electric Vehicle Co. Ltd.

Shares of lithium-ion battery technology company Ener1, Inc. (NASDAQ: HEV) (market cap $292 million) had plunged more than 27% by mid-day after the company reported at the market close Tuesday that it increased Q1 2011 revenues but suffered major net losses largely attributed to the write-down of the company’s 48% investment in Think Holdings, AS, a Norwegian electric vehicle manufacturer.

Shares of Ener1, Inc. (NASDAQ: HEV) closed up 14 percent Tuesday (down from 25 percent earlier in the day) after announcing prior to the market open that it had signed a joint venture agreement with Wanxiang Electric Vehicle Co., Ltd. to co-manufacture lithium ion cells and battery packs for the Chinese market. 

Ener1 shares are up 43 percent over the past six months, but down 19 percent over the past year.